diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 20d26f7ee5fa..8a76bde68948 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -106,6 +106,11 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - if: matrix.build-mode == 'manual'
+      name: Setup .NET 9.0
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - if: matrix.build-mode == 'manual'
       shell: bash
       working-directory: dotnet
diff --git a/.github/workflows/dotnet-build.yml b/.github/workflows/dotnet-build.yml
index a485f9ddd799..3d83bdf39d19 100644
--- a/.github/workflows/dotnet-build.yml
+++ b/.github/workflows/dotnet-build.yml
@@ -81,6 +81,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Restore dependencies
       run: dotnet restore -bl
     - name: Format check
@@ -207,6 +211,10 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: '8.0.x'
+    - name: Setup .NET 9.0
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
 
     - name: publish AOT testApp, assert static analysis warning count, and run the app
       shell: pwsh
@@ -249,6 +257,10 @@ jobs:
       with:
         dotnet-version: '8.0.x'
         global-json-file: dotnet/global.json
+    - name: Setup .NET 9.0
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '9.0.x'
     - name: Install dev certs
       run:  dotnet --version && dotnet dev-certs https --trust
     - name: Restore dependencies
diff --git a/dotnet/.tools/test-aot-compatibility.ps1 b/dotnet/.tools/test-aot-compatibility.ps1
index d70139fd1fd2..2579d3fef6d3 100644
--- a/dotnet/.tools/test-aot-compatibility.ps1
+++ b/dotnet/.tools/test-aot-compatibility.ps1
@@ -15,7 +15,7 @@ foreach ($line in $($publishOutput -split "`r`n"))
     }
 }
 
-pushd $rootDirectory/artifacts/bin/AutoGen.AotCompatibility.Tests/release
+pushd $rootDirectory/artifacts/bin/AutoGen.AotCompatibility.Tests/release/native
 
 Write-Host "Executing test App..."
 ./AutoGen.AotCompatibility.Tests
diff --git a/dotnet/global.json b/dotnet/global.json
index 4f9e9b79a15a..cdbb589edad7 100644
--- a/dotnet/global.json
+++ b/dotnet/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.401",
-    "rollForward": "latestMinor"
+    "version": "9.0.100",
+    "rollForward": "latestFeature"
   }
 }
diff --git a/dotnet/samples/AgentChat/AutoGen.OpenAI.Sample/Tool_Call_With_Ollama_And_LiteLLM.cs b/dotnet/samples/AgentChat/AutoGen.OpenAI.Sample/Tool_Call_With_Ollama_And_LiteLLM.cs
index 05c09f49dfdd..687281b3219f 100644
--- a/dotnet/samples/AgentChat/AutoGen.OpenAI.Sample/Tool_Call_With_Ollama_And_LiteLLM.cs
+++ b/dotnet/samples/AgentChat/AutoGen.OpenAI.Sample/Tool_Call_With_Ollama_And_LiteLLM.cs
@@ -42,8 +42,6 @@ public static async Task RunAsync()
             });
         #endregion Create_tools
         #region Create_Agent
-        var liteLLMUrl = "http://localhost:4000";
-
         // api-key is not required for local server
         // so you can use any string here
         var openAIClient = new OpenAIClient(new ApiKeyCredential("api-key"), new OpenAIClientOptions
@@ -59,7 +57,7 @@ public static async Task RunAsync()
             .RegisterMiddleware(functionMiddleware)
             .RegisterPrintMessage();
 
-        var reply = await agent.SendAsync("what's the weather in new york");
+        await agent.SendAsync("what's the weather in new york");
         #endregion Create_Agent
     }
 }
diff --git a/dotnet/samples/AgentChat/AutoGen.WebAPI.Sample/Program.cs b/dotnet/samples/AgentChat/AutoGen.WebAPI.Sample/Program.cs
index 18ce4b023907..315ac00554fa 100644
--- a/dotnet/samples/AgentChat/AutoGen.WebAPI.Sample/Program.cs
+++ b/dotnet/samples/AgentChat/AutoGen.WebAPI.Sample/Program.cs
@@ -40,6 +40,6 @@ public async IAsyncEnumerable<IMessage> GenerateStreamingReplyAsync(IEnumerable<
         foreach (var c in reply)
         {
             yield return new TextMessageUpdate(Role.Assistant, c.ToString(), this.Name);
-        };
+        }
     }
 }
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/ChatAgent.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/ChatAgent.cs
index 6cad4f88dfe2..b4cf2f738f46 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/ChatAgent.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/ChatAgent.cs
@@ -170,24 +170,23 @@ public interface IChatAgent :
     /// <summary>
     /// The name of the agent. This is used by team to uniquely identify the agent.It should be unique within the team.
     /// </summary>
-    AgentName Name { get; }
+    public AgentName Name { get; }
 
     /// <summary>
     /// The description of the agent. This is used by team to make decisions about which agents to use.The description
     /// should describe the agent's capabilities and how to interact with it.
     /// </summary>
-    string Description { get; }
+    public string Description { get; }
 
     /// <summary>
     /// The types of messages that the agent produces.
     /// </summary>
-    IEnumerable<Type> ProducedMessageTypes { get; } // TODO: Is there a way to make this part of the type somehow?
-                                                    // Annotations, or IProduce<>? Do we ever actually access this?
+    public IEnumerable<Type> ProducedMessageTypes { get; } // TODO: Is there a way to make this part of the type somehow? Annotations, or IProduce<>? Do we ever actually access this?
 
     /// <summary>
     /// Reset the agent to its initialization state.
     /// </summary>
     /// <param name="cancellationToken"></param>
     /// <returns></returns>
-    ValueTask ResetAsync(CancellationToken cancellationToken);
+    public ValueTask ResetAsync(CancellationToken cancellationToken);
 }
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/MessageHandling.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/MessageHandling.cs
index 4183723e8c81..4239e6135b8e 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/MessageHandling.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/MessageHandling.cs
@@ -5,22 +5,22 @@ namespace Microsoft.AutoGen.AgentChat.Abstractions;
 
 public interface IHandleChat<in TIn>
 {
-    ValueTask HandleAsync(TIn item)
+    public ValueTask HandleAsync(TIn item)
     {
         return this.HandleAsync(item, CancellationToken.None);
     }
 
-    ValueTask HandleAsync(TIn item, CancellationToken cancellationToken);
+    public ValueTask HandleAsync(TIn item, CancellationToken cancellationToken);
 }
 
 public interface IHandleChat<in TIn, TOut> // TODO: Map this to IHandle<> somehow?
 {
-    ValueTask<TOut> HandleAsync(TIn item)
+    public ValueTask<TOut> HandleAsync(TIn item)
     {
         return this.HandleAsync(item, CancellationToken.None);
     }
 
-    ValueTask<TOut> HandleAsync(TIn item, CancellationToken cancellationToken);
+    public ValueTask<TOut> HandleAsync(TIn item, CancellationToken cancellationToken);
 }
 
 public interface IHandleDefault : IHandleChat<object>
@@ -29,10 +29,10 @@ public interface IHandleDefault : IHandleChat<object>
 
 public interface IHandleStream<in TIn, TOut>
 {
-    IAsyncEnumerable<TOut> StreamAsync(TIn item)
+    public IAsyncEnumerable<TOut> StreamAsync(TIn item)
     {
         return this.StreamAsync(item, CancellationToken.None);
     }
 
-    IAsyncEnumerable<TOut> StreamAsync(TIn item, CancellationToken cancellationToken);
+    public IAsyncEnumerable<TOut> StreamAsync(TIn item, CancellationToken cancellationToken);
 }
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tasks.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tasks.cs
index 2b4d66d93bdd..1c11bbaa6c3d 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tasks.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tasks.cs
@@ -59,7 +59,7 @@ public interface ITaskRunner
     /// <param name="task">The task definition in text form.</param>
     /// <param name="cancellationToken"></param>
     /// <returns>The result of running the task.</returns>
-    async ValueTask<TaskResult> RunAsync(string task, CancellationToken cancellationToken = default) =>
+    public async ValueTask<TaskResult> RunAsync(string task, CancellationToken cancellationToken = default) =>
         await this.RunAsync(ToMessage(task)!, cancellationToken);
 
     /// <summary>
@@ -73,7 +73,7 @@ async ValueTask<TaskResult> RunAsync(string task, CancellationToken cancellation
     /// <param name="cancellationToken"></param>
     /// <returns>The result of running the task.</returns>
     /// <exception cref="InvalidOperationException">If no response is generated.</exception>
-    async ValueTask<TaskResult> RunAsync(ChatMessage task, CancellationToken cancellationToken = default)
+    public async ValueTask<TaskResult> RunAsync(ChatMessage task, CancellationToken cancellationToken = default)
     {
         await foreach (TaskFrame frame in this.StreamAsync(task, cancellationToken))
         {
@@ -98,7 +98,7 @@ async ValueTask<TaskResult> RunAsync(ChatMessage task, CancellationToken cancell
     /// <param name="cancellationToken"></param>
     /// <returns>A stream of <see cref="TaskFrame"/> containing internal messages and intermediate results followed by
     /// the final <see cref="TaskResult"/></returns>
-    IAsyncEnumerable<TaskFrame> StreamAsync(string task, CancellationToken cancellationToken = default) =>
+    public IAsyncEnumerable<TaskFrame> StreamAsync(string task, CancellationToken cancellationToken = default) =>
         this.StreamAsync(ToMessage(task), cancellationToken);
 
     /// <summary>
@@ -113,5 +113,5 @@ IAsyncEnumerable<TaskFrame> StreamAsync(string task, CancellationToken cancellat
     /// <param name="cancellationToken"></param>
     /// <returns>A stream of <see cref="TaskFrame"/> containing internal messages and intermediate results followed by
     /// the final <see cref="TaskResult"/></returns>
-    IAsyncEnumerable<TaskFrame> StreamAsync(ChatMessage? task, CancellationToken cancellationToken = default);
+    public IAsyncEnumerable<TaskFrame> StreamAsync(ChatMessage? task, CancellationToken cancellationToken = default);
 }
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Termination.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Termination.cs
index f5cb00cfe979..352b2529821d 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Termination.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Termination.cs
@@ -19,7 +19,7 @@ public interface ITerminationCondition
     /// <summary>
     /// Checks if the termination condition has been reached
     /// </summary>
-    bool IsTerminated { get; }
+    public bool IsTerminated { get; }
 
     /// <summary>
     /// Check if the conversation should be terminated based on the messages received
@@ -30,19 +30,19 @@ public interface ITerminationCondition
     /// <returns>A <see cref="StopMessage"/> if the conversation should be terminated, or <c>null</c>
     /// otherwise.</returns>
     /// <exception cref="TerminatedException">If the termination condition has already been reached.</exception>
-    ValueTask<StopMessage?> CheckAndUpdateAsync(IList<AgentMessage> messages);
+    public ValueTask<StopMessage?> CheckAndUpdateAsync(IList<AgentMessage> messages);
 
     /// <summary>
     /// Resets the termination condition.
     /// </summary>
-    void Reset();
+    public void Reset();
 
     /// <summary>
     /// Combine this termination condition with another using a logical OR.
     /// </summary>
     /// <param name="other">Another termination condition.</param>
     /// <returns>The combined termination condition, with appropriate short-circuiting.</returns>
-    ITerminationCondition Or(ITerminationCondition other)
+    public ITerminationCondition Or(ITerminationCondition other)
     {
         return new CombinerCondition(CombinerCondition.Or, this, other);
     }
@@ -52,7 +52,7 @@ ITerminationCondition Or(ITerminationCondition other)
     /// </summary>
     /// <param name="other">Another termination condition.</param>
     /// <returns>The combined termination condition, with appropriate short-circuiting.</returns>
-    ITerminationCondition And(ITerminationCondition other)
+    public ITerminationCondition And(ITerminationCondition other)
     {
         return new CombinerCondition(CombinerCondition.And, this, other);
     }
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tools.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tools.cs
index fe10182d11bf..1c0c276b7bbf 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tools.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/Abstractions/Tools.cs
@@ -82,8 +82,8 @@ public static ParameterSchema Create(Type type, string name, bool isRequired = f
 /// </summary>
 public interface ITool
 {
-    string Name { get; }
-    string Description { get; }
+    public string Name { get; }
+    public string Description { get; }
 
     public IEnumerable<ParameterSchema> Parameters { get; }
     public Type ReturnType { get; }
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatBase.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatBase.cs
index 5192cac6d086..f6ec12ca8427 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatBase.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatBase.cs
@@ -114,7 +114,7 @@ public virtual TManager CreateChatManager(GroupChatOptions options)
             if (Activator.CreateInstance(typeof(TManager), options) is TManager result)
             {
                 return result;
-            };
+            }
         }
         catch (TargetInvocationException tie)
         {
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatHandlerRouter.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatHandlerRouter.cs
index 9855dcafb7ea..fabcc574df8d 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatHandlerRouter.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/GroupChatHandlerRouter.cs
@@ -11,8 +11,8 @@ namespace Microsoft.AutoGen.AgentChat.GroupChat;
 
 internal interface IGroupChatHandler : IHandle<GroupChatStart>, IHandle<GroupChatAgentResponse>, IHandle<object>
 {
-    void AttachMessagePublishServicer(MessagePublishServicer? servicer = null);
-    void DetachMessagePublishServicer() => this.AttachMessagePublishServicer(null);
+    public void AttachMessagePublishServicer(MessagePublishServicer? servicer = null);
+    public void DetachMessagePublishServicer() => this.AttachMessagePublishServicer(null);
 }
 
 internal sealed class GroupChatHandlerRouter<TManager> : HostableAgentAdapter,
diff --git a/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/OutputCollectorAgent.cs b/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/OutputCollectorAgent.cs
index d17fa266b6aa..3c9fd61019be 100644
--- a/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/OutputCollectorAgent.cs
+++ b/dotnet/src/Microsoft.AutoGen/AgentChat/GroupChat/OutputCollectorAgent.cs
@@ -11,8 +11,8 @@ namespace Microsoft.AutoGen.AgentChat.Abstractions;
 
 internal interface IOutputCollectionSink
 {
-    void CollectMessage(AgentMessage message);
-    void Terminate(StopMessage message);
+    public void CollectMessage(AgentMessage message);
+    public void Terminate(StopMessage message);
 }
 
 internal sealed class OutputSink : IOutputCollectionSink
diff --git a/dotnet/src/Microsoft.AutoGen/Core.Grpc/GrpcMessageRouter.cs b/dotnet/src/Microsoft.AutoGen/Core.Grpc/GrpcMessageRouter.cs
index 32317cbc7a30..26d3827b0ff3 100644
--- a/dotnet/src/Microsoft.AutoGen/Core.Grpc/GrpcMessageRouter.cs
+++ b/dotnet/src/Microsoft.AutoGen/Core.Grpc/GrpcMessageRouter.cs
@@ -43,7 +43,7 @@ public void EnsureConnected()
         if (this.RecreateChannel(null) == null)
         {
             throw new Exception("Failed to connect to gRPC endpoint.");
-        };
+        }
     }
 
     public AsyncDuplexStreamingCall<Message, Message> StreamingCall
@@ -117,8 +117,9 @@ internal sealed class GrpcMessageRouter(AgentRpc.AgentRpcClient client,
     private readonly CancellationTokenSource _shutdownCts = CancellationTokenSource.CreateLinkedTokenSource(shutdownCancellation);
 
     private readonly IMessageSink<Message> _incomingMessageSink = incomingMessageSink;
+
+    // TODO: Enable a way to configure the channel options
     private readonly Channel<(Message Message, TaskCompletionSource WriteCompletionSource)> _outboundMessagesChannel
-        // TODO: Enable a way to configure the channel options
         = Channel.CreateBounded<(Message, TaskCompletionSource)>(DefaultChannelOptions);
 
     private readonly AutoRestartChannel _incomingMessageChannel = new AutoRestartChannel(client, clientId, logger, shutdownCancellation);
diff --git a/dotnet/src/Microsoft.AutoGen/Core/ResultSink.cs b/dotnet/src/Microsoft.AutoGen/Core/ResultSink.cs
index d103bdfda621..ef8958366a7b 100644
--- a/dotnet/src/Microsoft.AutoGen/Core/ResultSink.cs
+++ b/dotnet/src/Microsoft.AutoGen/Core/ResultSink.cs
@@ -7,11 +7,11 @@ namespace Microsoft.AutoGen.Core;
 
 internal interface IResultSink<TResult> : IValueTaskSource<TResult>
 {
-    void SetResult(TResult result);
-    void SetException(Exception exception);
-    void SetCancelled();
+    public void SetResult(TResult result);
+    public void SetException(Exception exception);
+    public void SetCancelled();
 
-    ValueTask<TResult> Future { get; }
+    public ValueTask<TResult> Future { get; }
 }
 
 public sealed class ResultSink<TResult> : IResultSink<TResult>
diff --git a/dotnet/src/Microsoft.AutoGen/RuntimeGateway.Grpc/Services/Grpc/GrpcGateway.cs b/dotnet/src/Microsoft.AutoGen/RuntimeGateway.Grpc/Services/Grpc/GrpcGateway.cs
index e657ac36fef0..97bc8df3f425 100644
--- a/dotnet/src/Microsoft.AutoGen/RuntimeGateway.Grpc/Services/Grpc/GrpcGateway.cs
+++ b/dotnet/src/Microsoft.AutoGen/RuntimeGateway.Grpc/Services/Grpc/GrpcGateway.cs
@@ -243,7 +243,7 @@ internal async Task OnReceivedMessageAsync(GrpcWorkerConnection connection, Mess
             default:
                 await RespondBadRequestAsync(connection, $"Unknown message type for message '{message}'.");
                 break;
-        };
+        }
     }
 
     /// <summary>
diff --git a/dotnet/test/AutoGen.AotCompatibility.Tests/AutoGen.AotCompatibility.Tests.csproj b/dotnet/test/AutoGen.AotCompatibility.Tests/AutoGen.AotCompatibility.Tests.csproj
index 379bca541012..aec9660bb922 100644
--- a/dotnet/test/AutoGen.AotCompatibility.Tests/AutoGen.AotCompatibility.Tests.csproj
+++ b/dotnet/test/AutoGen.AotCompatibility.Tests/AutoGen.AotCompatibility.Tests.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <PublishAot>true</PublishAot>
diff --git a/dotnet/test/AutoGen.Tests/MiddlewareTest.cs b/dotnet/test/AutoGen.Tests/MiddlewareTest.cs
index 564406ec7469..7dd48fec646b 100644
--- a/dotnet/test/AutoGen.Tests/MiddlewareTest.cs
+++ b/dotnet/test/AutoGen.Tests/MiddlewareTest.cs
@@ -72,7 +72,7 @@ public async Task HumanInputMiddlewareTestAsync()
     public async Task FunctionCallMiddlewareTestAsync()
     {
         var agent = new EchoAgent("echo");
-        var args = new EchoSchema { message = "hello" };
+        var args = new AutoGen.Tests.MiddlewareTest.EchoSchema { message = "hello" }; // make the format check happy on linux
         var argsJson = JsonSerializer.Serialize(args) ?? throw new InvalidOperationException("Failed to serialize args");
         var functionCall = new ToolCall("Echo", argsJson);
         var functionCallAgent = agent.RegisterMiddleware(async (messages, options, agent, ct) =>
diff --git a/dotnet/test/Microsoft.AutoGen.Core.Grpc.Tests/TestGrpcWorkerConnection.cs b/dotnet/test/Microsoft.AutoGen.Core.Grpc.Tests/TestGrpcWorkerConnection.cs
index 20b8169db11f..2a4d9ea0ac53 100644
--- a/dotnet/test/Microsoft.AutoGen.Core.Grpc.Tests/TestGrpcWorkerConnection.cs
+++ b/dotnet/test/Microsoft.AutoGen.Core.Grpc.Tests/TestGrpcWorkerConnection.cs
@@ -92,7 +92,7 @@ public async Task RunReadPump()
                     default:
                         // if it wasn't recognized return bad request
                         throw new RpcException(new Status(StatusCode.InvalidArgument, $"Unknown message type for message '{message}'"));
-                };
+                }
             }
         }
         catch (OperationCanceledException)